The invention relates to electrostatic descalers for water systems.
Electrostatic descaling is to be distinguished from the process of preventing corrosion in a water system by providing a sacrificial anode. In the latter, an electrical current flows through the water, and the anode is in electrical contact with the water. The electrical voltage is only a few volts. In electrostatic descaling, the voltage is often thousands of volts, and the electrode has to be well insulated from the water: no current flows through the water since the de-scaling effect is dependent on the electrostatic field.
Hard water contains calcium and magnesium salts and compounds (particularly carbonates) that precipitate out of the water and form scale on metal surfaces, particularly hot metal surfaces. A tiny particle of suspended matter can act as a nucleus on which the precipitate readily builds up. An electrostatic field ionizes these tiny particles so that they no longer promote nucleation. Hence, the hard salts in the water tend to pass straight through the system without being deposited as scale.
If an electrostatic field is applied to an existing system that has scale, then again the field acts to break up the nucleus. The scale loses all its strength and adhesion through this action, and can be easily flushed away.